Transfer and comminuting device



Oct. 7, 1958 w. H. LANNERT TRANSFER AND COMMINUTING DEVICE 5 Sheets-Sheet 1 Filed Dec. 27, 1954 W. H. LANNERT TRANSFER AND COMMINUTING DEVICE 3 Sheets-Sheet 2 Filed Dec. 2'7, 1954 Oct. 7, 1958 w. H. LANNERT I 2,355,102

TRANSFER AND COMM'INUTING DEVICE Filed Dec. 27, 1954 5 Sheets-Sheet :5

United States Patent TRANSFER AND COMMINUTING DEVICE William H. Lannert, Skokie, 11]., assignor to Chicago Pump Company, a corporation of Delaware Application December 27, 1954, Serial No. 477,605

8 Claims. (Cl. 210-159) This invention relates to a transfer and comminuting device, and more particularly to a helper rake for pushing solids, intercepted by a screen in a flowing stream of sewage, along the surface of the screen to an area from which they may be easily transferred to a comminuting device for comminution.

In accordance with the present invention an inclined screen extending across an influent channel through which a stream of sewage flows intercepts all solids too large to pass therethrough. A cutting cylinder is rotatably mounted above the screen and adjacent the upper end of the screen. The screen is provided with transversely spaced, longitudinally extending parallel screen elements, and the cylinder is provided with a plurality of series of laterally projecting teeth that are aligned transversely with the spaces between screen elements. The laterally projecting teethare adapted to carry solids from the screen and transfer them to the vicinity of a comb. The teeth cooperate with notches provided in one edge of the comb to comminute the solids that are interengaged by the teeth and comb. The position of the cylinder is fixed relative to the screen and therefore the teeth of the cylinder can reach only the solids that have been intercepted by the screen in immediate proximity to the cylinder.

In order to bring the cutting cylinder into engagement with the solids intercepted by the screen throughout the surface area of the screen, it has been proposed to have the cutting cylinder reciprocate in a longitudinal or horizontal direction adjacent the screen surface so that the entire surface area of the screen is periodically swept by the cutting cylinder. This type of .structure has proved to be satisfactory in operation, but is relatively costly to make, operate and maintain, and is generally not feasible for small operations.

Another method of bringing the cutting cylinder into engagement with the solids intercepted by the screen throughout the surface area of the screen is to provide a hopper beyond and below the upper end of the screen, and to move fingers longitudinally of the screen to push the solids from the surface of the screen into the hopper. The cutting cylinder forms one wall of the hopper and is adapted to pick the solids from the hopper and transfer them to the comminuting zone.

It has also been proposed to provide the cutting cylinder with laterally projecting tines as disclosed and claimed in the copending application of Carl H. Nordell, filed December 17, 1951, under Serial No. 261,973, which issued as Patent No. 2,750,044, June 12, 1956. In this structure tines project from the cutting cylinder and rotate therewith. The tines are extended their maximum distance as they pass upwardly through the screen and are gradually retracted as they approach the comb positioned adjacent the uppermost surface of the cylinder. As the tines pass through the screen they lift solids intercepted by the screen, and these solids move downwardly towards the cutting cylinder by gravity as the tines are rotated upwardly. The necessity of retracting the tines as they pass the comb imposes a limitation on the maximum length of the tines and, as a consequence, the tines cannot extend far enough to remove solids from the entire surface area of the screen.

The present invention contemplates the provision of means in combination with the screen and cylinder to periodically sweep or rake the screen and transfer the intercepted solids from the remote areas of the screen to the area of the screen within the range of the tines, if tines are provided, or to the range of the teeth of the cylinder, if no tines are provided, so that all the solids intercepted by the screen may be transferred to the cylinder which carries them to the cutting comb for comminution.

The present invention contemplates the provision of a simple, inexpensive rake capable of engaging solids intercepted by the screen outside the range covered by the teeth of the cylinder, or by the tines, if tines are provided, and moving the solids upwardly along the upper surface of the screen into the area which is reached by the teeth or by the tines. The teeth or the tines pick up the solids intercepted by the screen within the area reached by .them, and the solids moved into such area by the rake.

If tines are provided, their upward rotation causes these solids to move downwardly by gravity into engagement with the cutting cylinder. The teeth of the cutting cylinder carry the solids to the area adjacent the comb and cooperate with notches in the comb to comminute the solids. The device of the present invention is particularly suitable for use in sewage operations in small cities and towns where the amounts of sewage to be treated are relatively small.

The structure by which the above mentioned and other advantages of the invention are attained will be described in the following specification, taken in conjunction with the accompanying drawings, showing a preferred illustrative embodiment of the invention, in which:

Figure l is a fragmentary perspective view of a channel through which a stream of sewage flows, an inclined screen extending across the channel with its screen elements spaced transversely, a rake having fingers extending between the screen elements, and a comminuting device mounted adjacent the upper end of the screen all in accordance with the present invention;

Fig. 2 is a longitudinal sectional view, taken along the line 22 of Fig. 1, showing the rake and the means for moving it along the screen to push solids, intercepted by the screen in the area remote from the teeth, from such remote area to the area reached by the teeth which project laterally from the cutting cylinder;

Fig. 3 is a cross sectional view, taken along the line 33 of Fig. 2;

Fig. 4 is a fragmentary perspective view of the rake and guide member in disassembled relationship;

Fig. 5 is a fragmentary side view showing the rake at the upper end of its reciprocatory movement, the solid line indicating the rake at the end of its upward movement, and the dotted line showing it at the start of its downward movement;

Fig. 6 is a view, similar to Fig. 5, showing the rake at an intermediate point, the solid line showing the rake being moved upwardly, and the dotted line showing it being moved downwardly; and

Fig. 7 is a view, similar to Fig. 5, showing the rake at the lower end of its movement, the solid line showing the rake at the end of its downward movement, and the dotted line showing it at the start of its upward movement.

In the drawings, reference numeral 2 indicates an influent channel through which flows unscreened sewage carrying solids, and 3 indicates the efiluent channel through which the screened sewage flows, along with the solids that are comminuted adjacent the upper end of the screen on which they accumulate. Channels 2 and 3 are parts of a single structure, preferably made of concrete.

A screen 4 is supported in inclined position in channel 2 by means of a pair of standards 5 extending upwardly from the bottom of the channel. Any form of vscreen may be used. The illustrative embodiment of the screen shown in the drawings comprises a plurality of flat metal ribbons disposed edgewise and held in parallel trans- 'versely spaced relationship. Suitable supports extending laterally from the side walls of the channel can be used instead of standards 5, to support the upper end of screen 4, if desired. The lower end of the screen can be secured to the bottom of channel 2 in any suitable manner. The screen is illustrated as being inclined at approximately thirty degrees, but it will be understood that this angle may be varied, as desired.

Screen4 comprises a frame 6 the outer edges of which are'flush against the walls of influent channel 2. Frame 6 is provided with a centrally disposed opening 7 across which a plurality of individual screen elements 8 extend. These screen elements are disposed edgewise and longitudinally of the screen, and are transversely spaced across the space between the longitudinal edges of frame ,6. The screen elements are held under tension by any suitable means, such as the tensioning device described and claimed in the copending application of Carl H. Nordell, filed March 26, 1954, under Serial No. 418,944, which issued December 20, 1955, as Patent No. 2,727,627. The tensionirig device includes a plurality of individual leaf springs 9 each holding the upper end of a screen element 8. The leaf spring extends past a rib 10 projecting from a plate 11 and is held in place by a bolt 12. The edgewise disposition of individual screen elements in a screen is claimed in the copending application of Carl H. Nordell, filed August 20, 1954, under Serial No. 451,130, as a continuation-in-part of application Serial No. 278,822, now abandoned, which was filed March 27, 1952, as a division of application Serial No. 261,973, filed December 17, 1951, which issued June 12, 1956, as Patent No. 2,750,044. a

A cutting cylinder l3, disposed horizontally relative to the screen, is rotatably mounted in bearings 14 supported on brackets 15 secured to the upper surface of frame 6. The cutting cylinder is provided at one end with a housing 16 which contains gears (not shown) operatively connected to a motor 17 for rotating the cylinder. Cylinder 13 is provided with a plurality of series of laterally extending teeth 18. The teeth are spaced longitudinally of the cylinder to coincide with the spacing between individual screen elements so that they enter the spaces be- .tween adjacent screen elements 8 as the cylinder rotates.

A stationary comb 19, secured to housing 16 extends parallel to the longitudinal axis of cutting cylinder 13 and is positioned adjacent the peripheral surface of the -cylinder along a line spaced radially from the line of contact between said cylinder and screen elements 8. Comb 19 is provided with longitudinally spaced notches or recesses 20 aligned with teeth 18 which cooperate -therewith to comminute solids carried by the teeth as they pass through the notches.

The solids that are intercepted by the screen within the area reached by teeth 18 are engaged by the teeth and carried by said teeth along the portion of the periphery ofcutting" cylinder 13 to the comb. The solids remain against the comb until they are forced through notches 20. In being so forced the solids are comminuted, and pass through the screen and into effluent channel 3 along withthe flowing sewage stream that also passes through the screen.

A transfer device or rake, adapted to be reciprocated longitudinally of the screen, is provided for the purpose of pushing solids that are intercepted by the portion of the screen out of the range of teeth 18 upwardly along the screen into the range of the teeth. The transfer device comprises a plurality of short fingers 21 rigidly secured in transversely spaced relationship to a bar 22. In the embodiment illustrated bar 22 is in the form of an angle iron, but it will be understood that it may be of any desired shape. Each finger is positioned between adjacent screen elements 8 and is of substantially the same thickness as the distance between adjacent screen elements so that the fingers will wipe the screen elements clean as the rake is moved longitudinally of the screen towards cylinder 13.

The structure at opposite longitudinal edges of screen frame 6 is the same, and therefore the structure on only one side will be described. The longitudinal edge of screen frame 6 is provided with a downwardly extending flange 23 fitting against the walls of channel 2. A guide member 24 is rigidly secured to flange 23 with its side wall 25 fitting against the inner surface of the flange. Guide member 24 has a top wall 26 and a bottomwall 27 extending inwardly at right angles to side wall 25. The top wall 26 of the guide member is provided with a downwardly curved resilient extension 28 of spring steel at its lower end and a similar downwardly curved extension 29 at its upper end. The lower wall 27 is provided at its lower end with a similar extension 30 parallel to extension 28 and at its upper end with a similar extension 31 parallel to extension 29.

The rake structure is the same at both ends and therefore only one end will be described. A flat plate 32 is rigidly secured to the end of bar 22. A link 33 pivotally connected at one end to plate 32, as indicated at 34, is pivotally connected at its other end to a clevis 35, as indicated at 36. Clevis 35 is secured to one end of a rod 37. The opposite end of rod 37 is connected to a crosshead 38. A cylinder 39, disposed centrally in the upper portion of frame 6 is provided with a piston .rod 40 Secured vat its end to crosshead 38. Cylinder 39 is operated by a conventional hydraulic system, and reciprocation of piston rod 40 reciprocates the rake longitudinally of the screen.

A fiat bar 41 is mounted on a stud .42 projecting outwardly from plate 32. Plate 32 and bar 41 are each movable pivotally relative to stud 42. Stud 42 is provided on its outer end with a roller 43 rotatably mounted in guide member 24. The diameter of roller 43 is approximately equal to the distance between top and bottom walls 26 and 27 of the guide member. A roller 44, similar to roller 43, is mounted on a stud 45 projecting outwardly from bar 41. Rollers43 and 44 are aligned with each other and are thesame size-so that they fit snugly in guide member 24 in longitudinally spaced relationship. Bar 41 is also provided with pins 46 and 47 projecting into the plane of plate 32. Pins 46 and 47 serve as stop members to limit the pivotal movement of plate 32 about stud 42, pin 46 abutting one edge of plate 32 when the plate extends perpendicularly to bar 41 and pin 47abutting the opposite edge of the plate when the upper end of the plate is pushed forwardly by rod 37.

The operation of the, rake mechanism is very simple. As piston rod 40 pulls the rake upwardly longitudinally of the screen, plate 32 is pulled rearwardly against pin 46 to hold rake fingers 21 perpendicular to bar 41. In this position the length of fingers 21 causes them to project above the upper surface of screen elements '8 ,so that all solids intercepted by the screen are pushed upwardly along the surface of the screen until piston rod 40 is fully retracted. At the upper end of its movement the rake is positioned with its fingers in proximity to cylinder 13, and rotation of the cylinder causes teeth 18 to pick the solids from the surface of the screen and carry them to comb 19 for comminution.

The downwardly extending curve between extensions 29 and 31 of the guide member retards the movement of roller 44 in. the opposite direction. This retarding effect is 'sufiicient to cause rod. 37 to push plate 32 pivotally about stud 42 until it abuts pin 47. In this position rake fingers are inclined forwardly, as shown in dotted lines in Fig. 5. Continued downward movement of piston rod 40 lifts roller 44 up the curved surface of extension 31. Since the rear end of bar 41 is raised with roller 44, pin 47 is moved forwardly and downwardly. Ths piston continues to push plate 32 forwardly against pin 47 thereby causing the plate and the rake fingers to be inclined even further so as to bring the upper edges of the rake fingers approximately flush with the upper surface of screen elements 8, as shown in dotted lines in Fig. 6. The rake fingers remain in this position throughout the downward movement of the rake until roller 43 reaches the extension 30 at the forward end of its movement. The retraction of rake fingers 21 enables them to move downwardly along the screen without disturbing the solids that have been intercepted by the screen.

The movement of roller 43 on to extension 30 moves rake fingers to the position shown in solid lines in Fig. 7 and resists upward movement of the rake until plate 32 is pulled upwardly into abutting relationship with pin 46. Continued upward movement of piston rod 40 lifts roller 43 on to bottom wall 27 of the guide member and causes the rake fingers to project above the upper surface of the screen for the upward movement of the rake.

While I have described a preferred embodiment of my invention in considerable detail, it will be understood that the description thereof is intended to be illustrative, rather than restrictive, as many details may be modified or changed without departing from the spirit or scope of the invention. For example, the cylinder 39 may be replaced by a pair of cylinders, one at each side of frame 6. The crosshead 38 would then be unnecessary, and the piston rod of each cylinder could be secured directly to one of the links 33. Accordingly, I do not desire tov be restricted to the exact structure described.

I claim:

1. In combination with an inclined screen having a plurality of longitudinally extending screen elements, a guide member extending parallel to said screen adjacent a longitudinal edge thereof, a rake positioned below said screen and extending transversely thereof, means for reciprocating said rake longitudinally relative to said screen, said rake having a plurality of fingers extending upwardly between said screen elements, a plate rigidly secured to one end of said rake, a stud rotatably mounted in said'plate, said stud projecting outwardly along a line parallel to said rake, a bar rotatably mounted on said stud, a pair of stop pins rigidly mounted in said bar, said pins projecting inwardly into the plane of said plate, a second stud projecting outwardly from said bar, a roller rotatably mounted on the outer end of each of said studs, both of said rollers being mounted in said guide member, said reciprocating means being operatively connected to said plate whereby it pulls one edge of said plate against one of said pins when said rake is being moved upwardly along said screen and pushes the opposite edge of said plate against said other pin when said rake is being moved downwardly along said screen.

2. In combination with an inclined screen having a plurality of transversely spaced longitudinally extending screen elements, a guide member extending parallel to said screen adjacent opposite longitudinal edges thereof, each of said guide members terminating at each end in a downwardly curved extension, a rake positioned below said screen and extending transversely thereof, said rake having a plurality of fingers extending upwardly between said screen elements, a pair of rollers positioned in each of said guide members and operatively connected to opposite ends of said rake, means for reciprocating said rake longitudinally of said screen, said downwardly curved extensions cooperating with one roller of each of said pairs of rollers at each end of the reciprocatory movement to cause said reciprocating means to move said 6 rake angularly between two predetermined positions upon each change of longitudinal direction of movement of said rake.

3. In combination with an inclined screen having a plurality of transversely spaced longitudinally extending screen elements, a guide member extending parallel to said screen adjacent opposite longitudinal edges thereof, each of said guide members terminating at each end in a downwardly curved extension, a rake positioned below said screen and extending transversely thereof, said rake having a plurality of fingers extending upwardly between said screen elements, a pair of rollers positioned in each of said guide members and operatively connected to opposite ends of said rake, a bar mounted between each end of said rake and the adjacent pair of rollers, a pair of pins projecting into the plane of said rake from each of said bars, means for reciprocating said rake longitudinally of said screen, said reciprocating means pulling said rake against one pin of each of said pairs of pins to project said rake fingers above the upper surface of said screen elements as it moves said rake upwardly along said screen, and pushing said rake against the other pin of each pair of pins to retract the rake fingers below the upper surface of said screen elements as it moves said rake downwardly along said screen.

4. In combination with an inclined screen having a plurality of transversely spaced longitudinally extending screen elements, a guide member extending parallel to said screen adjacent opposite longitudinal edges thereof, each of said guide members terminating at each end in a downwardly curved extension, a rake positioned below said screen and extending transversely thereof, said rake having a plurality of fingers extending upwardly between said screen elements, a pair of rollers positioned in each of said guide members and operatively connected to opposite ends of said rake, a bar mounted between each end of said rake and the adjacent pair of rollers, a pair of pins projecting into the plane of said rake from each of said bars, said rake being movable angularly between the pins of each pair to project said rake fingers above the upper surface of said screen elements or to retract said rake fingers, and means for reciprocating said rake longitudinally of said screen, said downwardly curved extensions exerting a retarding action against longitudinal movement of said rake at each change of direction of said reciproe eating means whereby said reciprocatory means moves said rake angularly between said pins uponeach change of longitudinal direction of movement of said rake.

5. In combination with an inclined screen having a plurality of transversely spaced longitudinally extending screen elements, a rake positioned below said screen and extending transversely thereof, said rake having a plurality of fingers extending upwardly between said screen elements, means for reciprocating said rake, and a guide member for guiding said rake longitudinally of said screen, said guide member being curved at each end thereof, the curved ends of said guide member cooperating with said reciprocatory means and said rake to move the fingers of said rake angularly between said screen elements at each change of direction of longitudinal movement of said rake.

6. In combination with an inclined screen comprising a frame and a plurality of transversely spaced screen elements extending longitudinally of said frame, said frame having two longitudinal side walls each provided with a depending flange, a single guide channel secured to each of said flanges, a rake positioned belowsaid screen and extending transversely thereof, said rake having rollers mounted in each of said guide channels and fingers extending upwardly between said screen elements, means for reciprocating said rake longitudinally of said screen, and curved ends on said guide channels cooperaitng with said rollers and said reciprocating means to move said rake angularly at each change of direction of its longitudinal movement, whereby said fingers are projected above the upper surface, of said screenelementsassaid side wall, a top wall,v and a bottom wall extending at right angles to said side wall, a rake, a plate rigidly secured to one end of said rake, a stud rotatably mounted in said plate, said stud projecting outwardly along a line parallel to said rake, a bar rotatably mounted on said stud, a pair of stop pins rigidly mounted in said bar, said pins projecting inwardly into the plane of said plate, a second stud projecting outwardly from said bar, a roller rotatably mounted on the outer end of each of said studs, both of said rollers being mounted in said guide member, and means for reciprocating said rake longitudinally relativeto said guide member, said reciprocating means being voperatively connected to said plate, whereby it pulls one edge of said plate against one of said pins when said rake is being moved in one direction, and pushes the opposite edge of said plate against said other pin when said rake is being moved in the opposite direction.

8. In combination, a pair of guide members extending parallel to each other, each of said guide members terminating at each end in a downwardly curved extension,

a paireof -ro1le rs posit ioned in each .of. said guide..members,.a rake, eachof saidpairsof rollers being operativcly connected to opposite ends of said rake, and means for reciprocating said rake longitudinally relative to said guide members, said downwardly .curved extensions cooperating with one roller of each of said pairs of rollers at each end of the reciprocatory movement of said rake to cause said reciprocating means to move said rake angularly between two predetermined positions uponv each chage of longitudinal direction of movement of said rake.

References Cited in the file of this, patent UNITED STATES PATENTS Re. 14,176 Hersler Aug. 1, 1916 452,595 Correll May 19, 1891 1,426,648 Johns Aug. 22, 1922 1,799,457 Cuttle et a1 Apr. 7, 1931 2,684,157 Tolman July 20, 1954 FOREIGN PATENTS 391,935 Great Britain May 11, 1933 590,146 Great Britain July 9, 1947 

